CN115094637A - A three-proof finishing process of pure cotton fabric - Google Patents

Abstract

The invention provides a three-proof finishing process for pure cotton fabrics. The main process flow is as follows: drying wool→mercerizing→drying→etching wool→dyeing→drying→setting (three-proofing finishing)→pre-shrinking→winding. The setting process is as follows: (1) Put the pure cotton fabric on the setting machine (the bath ratio is 1:20, and the finishing liquid is silicone smoothing agent) → one dip and one rolling (rolling ratio 65-75%) → drying → setting → Finished product; (2) Put the cotton fabric after (1) treatment on the setting machine again (the bath ratio is 1:20, and the finishing liquid is three-proof finishing agent and cross-linking agent) → one dip and one rolling (rolling ratio 65 ‑75%)→drying→setting→finished product, so as to obtain three-proof pure cotton fabric. The finished cotton fabric has excellent waterproof, oil-proof and anti-fouling properties, and has good washing resistance. The fabric feels soft and smooth, and has a good market value.

Description

A three-proof finishing process of pure cotton fabric

technical field

The invention relates to a three-proof finishing process for pure cotton fabrics, belonging to the technical field of fabric finishing.

Background technique

As people's requirements for clothing are getting higher and higher, the concept of clothing consumption has also undergone great changes. People not only need to wear warm clothes, but also suitable clothes. Therefore, clothing should have more properties to meet more requirements. Functional textile products refer to textile products with other special functions in addition to the functions of keeping warm, covering and beautifying beyond conventional textile products, such as softness and elasticity, moisture absorption and quick drying, antistatic, anti-ultraviolet, flame retardant, antibacterial and deodorant Among them, the three-proof (waterproof, oilproof, antifouling) finishing is the most popular.

The three-proof finishing is to form a layer of polymer film with low surface energy on the surface of the fabric through physical and chemical action, without damaging the natural feel of the fabric, giving the fabric durable water-repellent, oil-repellent and stain-repellent properties. Liquid stains such as water and oil cannot be wetted and form small balls on the surface of the fabric and roll off. It does not close the pores of the fabric and maintains the original air permeability of the fabric, so that the hydrophilicity of the fabric is minimized and the hydrophobicity is optimal. .

As a textile fabric with a high usage rate, cotton fabric has the advantages of good warmth retention, soft hand feeling, easy cleaning, wear resistance and washing resistance, and good dyeing performance. Clothing made of cotton fabrics such as T-shirts, shirts, casual pants, etc. are worn It has good comfort and is deeply loved by consumers. Therefore, it is of great significance to study the three-proof finishing of cotton fabrics.

At present, the three-proof finishing agents on the market are mainly used for outdoor equipment such as swimming suits, mountaineering suits, and special clothing such as protective clothing. The application of ordinary cotton clothing is difficult to meet the needs of the market. For example, it is difficult to meet the general cotton clothing. Soft and smooth requirements and washing resistance.

SUMMARY OF THE INVENTION

The purpose of the invention is to overcome the defects of poor softness and washing resistance of ordinary pure cotton fabrics after finishing with three-proof finishing agent, and to provide a three-proof finishing process for pure cotton fabrics, so that the cotton fabrics after the three-proof finishing have three-proof effects. At the same time, it has the advantages of smooth and soft performance, and the washing resistance is improved, which meets the market demand for ordinary cotton clothing.

The technical scheme adopted by the present invention to solve its technical problems is:

A three-proof finishing process for pure cotton fabric, the process comprises the following steps in turn:

S1, Pretreatment of pure cotton fabrics

The pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

S2, the first stereotype finishing

Put the pretreated pure cotton fabric on the setting machine for one dipping and one rolling at a bath ratio of 1:20 (rolling rate 65-75%)→drying at 80-100℃→setting at 130-150℃→finishing process of finished product Carry out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is a silicone smoothing agent;

S3, the second stereotype finishing

The pure cotton fabric after S2 treatment is placed on the setting machine again, and the bath ratio is 1:20 for one dip and one rolling (rolling ratio 65-75%) → drying at 80-100 °C → setting at 150-170 °C → finishing of finished products The process carries out the second shaping finishing, wherein the finishing liquid in the rolling groove of the shaping machine is a combination of an appropriate amount of three-proof finishing agent and a cross-linking agent;

S4, pre-shrink, rewind

The finished pure cotton fabric is pre-shrinked → rolled to obtain a three-proof pure cotton fabric.

The three-proof finishing process of the pure cotton fabric of the present invention has the advantages of superior waterproof, oil-proof and anti-fouling performance, good washing resistance, soft and smooth fabric feel, and good market value.

Preferably, the organosilicon smoothing agent described in S2 is an organosilicon-modified waterborne polyurethane smoothing agent, and the amount thereof is 35-45 g/L. The preferred dosage is 40g/L.

As a preference, the vehicle speed in S2 is 35-45m/min, and the temperature is 130-150°C. Preferably 40m/min, 140°C.

Preferably, the three-proof finishing agent described in S3 is one of the short-chain C6 fluorine-containing three-proof finishing agents AG-E081 or AG-E0821, and the amount thereof is 55-65 g/L. AG-E081 is preferred, and the dosage is 60g/L.

Preferably, the cross-linking agent in S3 is one of polyvinyl alcohol-type cross-linking agents BP-24 or BP-26, and the amount thereof is 8-12 g/L. BP-24 is preferred, and the dosage is 10 g/L.

Preferably, it is characterized in that: the speed of the vehicle in S3 is 25-35m/min, and the temperature is 150-170°C. Preferably 30m/min, 160°C.

Preferably, in S2 and S3, the rolling ratio of one dip and one rolling is 65-75%.

As preferably, the preparation method of described organosilicon modified water-based polyurethane smoothing agent is:

(1) (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tris(hexamethylene)isocyanate, 1,6-hexanediol and poly Ethylene glycol monomethyl ether was mixed with molar ratio of 2:1:1 and reacted at 90℃±5℃ for 1.5h to 2h to synthesize urethane prepolymer, and then the blocking agent 3,5-dimethylpyrazole was added at 70 React at ℃ for 1h to 2h to synthesize blocked isocyanate, and the molar ratio of 3,5-dimethylpyrazole to urethane prepolymer is 3:1;

(2) The blocked isocyanate is added with 200 times to 250 times the mass of water, stirred at a speed of 1500 rpm to 2500 rpm for 30 min to 40 min to obtain a blocked isocyanate emulsion, which is uniformly mixed with amino silicone oil at a mass ratio of 1:1 to obtain an organic Silicon modified waterborne polyurethane smoothing agent.

Preferably, the amino silicone oil is TSF-4708 amino silicone oil.

The beneficial effects of the present invention are:

1. The present invention uses silicone-modified water-based polyurethane as the silicone smoothing agent during the first shaping and finishing. The smoothing agent can give the fabric a unique "soft and waxy but not greasy" feel style, and the fabric has good hydrophilicity. Less yellowing and good resilience, it can maintain the brightness of light-colored fabrics and the whiteness of white fabrics; compared with the common amino silicone oil softener TSF-4708, the blocked isocyanate in this smoother can interact with the surface of cotton fabrics - OH reaction, this chemical bond provides a strong covalent bond between the fabric and the softener, improves the dimensional stability of the cotton fabric, and makes the finished cotton fabric have good washing resistance.

2. The three-proof finishing agent used in the second shaping and finishing of the present invention is a short-chain C6 fluorine-containing three-proof finishing agent. This product can effectively prevent water and oily stains from penetrating into the fiber, and the finished fabric has good properties. Waterproof, oil-proof and stain-proof, it has little effect on the whiteness, hand feeling and air permeability of the fabric, and does not affect its wearability; compared with C8 fluorine-containing three-proof finishing agent 56085, it is more environmentally friendly, does not contain APEO, and has PFOS and PFOA All are lower than the detection limit; compared with the fluorine-free waterproof finishing agent XF-5001, it is more excellent in oil and antifouling performance.

3. The cross-linking agent used in the second shaping and finishing of the present invention is polyvinyl alcohol. This product can be combined with pure cotton fabric, three-proof finishing agent and water-based polyurethane smoothing agent through hydrogen bonds, so that the The surface of the cotton fabric forms a dense and tangled resin network, and the washing resistance of the cotton fabric after finishing is greatly improved, which meets the market demand and has good market promotion value.

Detailed ways

The technical solutions of the present invention will be further described in detail below through specific examples. It should be understood that the implementation of the present invention is not limited to the following examples, and any modifications and/or changes made to the present invention will fall within the protection scope of the present invention.

In the present invention, unless otherwise specified, all parts and percentages are in units of weight, and the equipment and raw materials used can be purchased from the market or commonly used in the art. The methods in the following examples, unless otherwise specified, are conventional methods in the art.

Organosilicon smoothing agent, organosilicon-modified water-based polyurethane smoothing agent, the preparation method of the organosilicon-modified water-based polyurethane smoothing agent is: (1) (2,4,6-trioxotriazine-1,3,5) (2H,4H,6H)-triyl)tris(hexamethylene)isocyanate, 1,6-hexanediol and polyethylene glycol monomethyl ether were mixed in a molar ratio of 2:1:1 and reacted at 90°C for 1.5 h Synthesize urethane prepolymer, then add blocking agent 3,5-dimethylpyrazole, mix with urethane prepolymer at a molar ratio of 3:1, react at 70 °C for 1 h to synthesize blocked isocyanate (2) stir 30min under the speed of 2000rpm on the homogenizer, add water to prepare blocked isocyanate emulsion (m _water : m _{blocked isocyanate} =200:1), with amino silicone oil softener TSF-4708 in mass ratio 1:1 After mixing evenly, the silicone modified water-based polyurethane smoothing agent is prepared;

Amino silicone oil softener TSF-4708, purchased from Zhejiang Transfar Energy Co., Ltd.;

Three-proof finishing agent, short-chain C6 fluorine-containing three-proof finishing agent AG-E081, AG-E082;

Fluorine-free waterproof finishing agent XF-5001, purchased from Suzhou Heming Textile Auxiliary Co., Ltd.;

C8 fluorine-containing three-proof finishing agent 56085, purchased from Shaoxing Weiqin Textile Auxiliary Co., Ltd.;

The cross-linking agent, polyvinyl alcohol type cross-linking agent BP-24 or BP-26, was purchased from Guangzhou Zhonggao Chemical Co., Ltd.

Example 1

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, put the pretreated pure cotton fabric on the setting machine and carry out one dip and one rolling (the rolling ratio is 65%) at a bath ratio of 1:20 → drying (80°C) → setting (130°C) → finishing of the finished product The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 35g/L silicone-modified water-based polyurethane smoothing agent, and the locomotive speed is 35m/min.

Step 3, place the pure cotton fabric treated in step 2 on the shaping machine again and carry out one dip and one rolling (rolling ratio 6%) at a bath ratio of 1:20 → drying (80° C.) → setting (150° C.) → finished product The finishing process was carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine was 55g/L three-proof finishing agent AG-E081, 8g/L crosslinking agent BP-26, and the locomotive speed was 25m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Example 2

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (90°C)→setting (140°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 40g/L silicone modified waterborne polyurethane smoothing agent, and the locomotive speed is 40m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (100°C)→setting (160°C)→finished product The finishing process was carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine was 60g/L three-proof finishing agent AG-E081, 10g/L crosslinking agent BP-24, and the locomotive speed was 30m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Example 3

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (the rolling ratio is 70%)→drying (100°C)→setting (150°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 45g/L silicone-modified water-based polyurethane smoothing agent, and the locomotive speed is 45m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again, and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 70%)→drying (90°C)→setting (170°C)→finished product The finishing process is carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine is 65g/L three-proof finishing agent AG-E082, 12g/L crosslinking agent BP-26, and the locomotive speed is 35m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Comparative Example 1

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (90°C)→setting (140°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 40g/L amino silicone oil softener TSF-4708, and the locomotive speed is 40m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (100°C)→setting (160°C)→finished product The finishing process was carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine was 60g/L three-proof finishing agent AG-E081, 10g/L crosslinking agent BP-24, and the locomotive speed was 30m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Comparative Example 2

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (90°C)→setting (140°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 40g/L silicone modified waterborne polyurethane smoothing agent, and the locomotive speed is 40m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (100°C)→setting (160°C)→finished product The finishing process is carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine is 60g/L three-proof finishing agent 56085, 10g/L crosslinking agent BP-24, and the locomotive speed is 30m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Comparative Example 3

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (90°C)→setting (140°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 40g/L silicone modified waterborne polyurethane smoothing agent, and the locomotive speed is 40m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (100°C)→setting (160°C)→finished product The finishing process is carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine is 60g/L fluorine-free waterproof finishing agent XF-5001, 10g/L crosslinking agent BP-24, and the locomotive speed is 30m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

Comparative Example 4

A three-proof finishing process for pure cotton fabric, after the pretreatment and dyeing process of the pure cotton fabric, the three-proof finishing is performed on the pure cotton fabric, and the specific steps are as follows:

Step 1, the pure cotton fabric is pretreated according to the process of drying wool→mercerizing→drying→etching wool→dyeing→drying.

Step 2, place the pretreated pure cotton fabric on the setting machine and carry out one dipping and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (90°C)→setting (140°C)→finishing of finished products The process carries out the first shaping finishing, in which the finishing liquid in the rolling groove of the shaping machine is 40g/L silicone modified waterborne polyurethane smoothing agent, and the locomotive speed is 40m/min.

Step 3, place the pure cotton fabric treated in step 2 on the setting machine again and carry out one dip and one rolling at a bath ratio of 1:20 (rolling ratio 75%)→drying (100°C)→setting (160°C)→finished product The finishing process is carried out for the second setting finishing, in which the finishing liquid in the rolling groove of the setting machine is 60g/L three-proof finishing agent AG-E081, and the locomotive speed is 30m/min.

Step 4, pre-shrinking the finished cotton fabric → winding to obtain a three-proof pure cotton fabric.

The three-proof pure cotton fabrics prepared under the process conditions described in Examples 1-3 and Comparative Examples 1-4 were tested, and the results are shown in Table 1.

Table 1

Washing process: wash 10 times/20 times at room temperature, 12min/cycle → add washing powder + washing cloth → wash 3 times with clean water → dry at 66°C → regain moisture → test performance

After washing 10 times at room temperature, the detection effect is shown in Table 2.

Table 2

After washing at room temperature for 20 times, the detection effect is shown in Table 3.

table 3

As shown in the indicators in Table 1, it can be seen that the three-proof cotton fabrics prepared under the process conditions described in Examples 1, 2, and 3 all have good waterproof, oil-proof, and anti-fouling properties, and feel soft and smooth. Among them, the preferred process conditions are examples The three-proof effect of 2 is slightly better than that of Example 1 and Example 3; and the content of perfluorooctane sulfonyl compound (PFOS) and perfluorooctanoic acid (PFOA) has reached the national standard and meets the requirements for taking.

It can be seen from Tables 2 and 3 that after 10 or 20 times of washing at room temperature, the examples still have good three-proofing effect, have little effect on the hand feeling of the fabric, and have good washing resistance.

Comparing Example 2 and Comparative Example 1, it can be seen that the softening effect of the silicone-modified water-based polyurethane smoothing agent is equivalent to that of the amino silicone oil softener TSF-4708, and both can give the fabric a soft feel, and after 20 washes, the silicone-modified The fabrics finished with water-based polyurethane smoothing agent still have a soft hand, and the effect is better than that of amino silicone oil softener TSF-4708.

Comparing Example 2 with Comparative Example 2 and Comparative Example 3, it can be seen that the three-proofing effect of the short-chain C6 fluorine-containing three-proofing finishing agent is equivalent to that of the C8 fluorine-containing three-proofing finishing agent, and is better than that of the fluorine-free waterproof finishing agent; The fluorine-containing three-proof finishing agent does not contain APEO, and both PFOS and PFOA are lower than the detection limit, and it is better than the C8 fluorine-containing three-proof finishing agent in terms of environmental protection.

Comparing Example 2 and Comparative Example 4, it can be seen that after adding the polyvinyl alcohol crosslinking agent to the finishing solution, the fabric has better washing resistance.

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the points that are different from other embodiments, and the same or similar parts between the various embodiments may be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

The three-proof finishing process of a pure cotton fabric provided by the present invention has been described in detail above. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (9)

1. A three-proofing finishing process of pure cotton fabrics is characterized by sequentially comprising the following steps:

s1 pretreatment of pure cotton fabric

Pretreating the pure cotton fabric according to the process of drying wool → mercerizing → drying → etching wool → dyeing → drying,

s2, first sizing and finishing

Placing the pretreated pure cotton fabric on a setting machine according to a bath ratio of 1: 20, performing first-time shaping and finishing by a finishing process of soaking and rolling → drying at 80-100 → shaping at 150 ℃ → finished product, wherein the finishing liquid in a rolling groove of the shaping machine is an organic silicon smoothing agent;

s3, second sizing and finishing

Placing the pure cotton fabric treated by the S2 on a setting machine again according to the bath ratio of 1: 20, performing a second shaping and finishing by a soaking and rolling process → 80-100 ℃ drying → 150-;

s4, preshrinking and rolling

And (4) performing preshrinking → rolling on the finished pure cotton fabric to obtain the three-proofing pure cotton fabric.

2. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: the organosilicon smoothing agent of S2 is organosilicon modified waterborne polyurethane smoothing agent, and the dosage is 35-45 g/L.

3. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: the speed of the sizing in S2 is 35-45m/min, and the temperature is 130-150 ℃.

4. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: s3, the three-proofing finishing agent is one of short-chain C6 fluorine-containing three-proofing finishing agents AG-E081 or AG-E082, and the dosage of the finishing agent is 55-65 g/L.

5. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: s3 the cross-linking agent is one of polyvinyl alcohol type cross-linking agents BP-24 or BP-26, and the dosage of the cross-linking agent is 8-12 g/L.

6. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: the speed of the sizing in S3 is 25-35m/min, and the temperature is 150-170 ℃.

7. The three-proofing finishing process of the pure cotton fabric according to claim 1, characterized in that: in S2 and S3, the mangle ratio of one-dip-one-roll is 65-75%.

8. The three-proofing finishing process of the pure cotton fabric according to claim 2, characterized in that: the preparation method of the organosilicon modified waterborne polyurethane smoothing agent comprises the following steps:

(1) mixing (2, 4, 6-trioxotriazine-1, 3, 5(2H, 4H, 6H) -triyl) tris (hexamethylene) isocyanate, 1, 6-hexanediol and polyethylene glycol monomethyl ether in a molar ratio of 2: 1: 1, mixing the mixture at 90 +/-5 ℃ for reacting for 1.5 to 2 hours to synthesize a carbamate prepolymer, adding a sealing agent 3, 5-dimethylpyrazole, and reacting at 70 ℃ for 1 to 2 hours to synthesize a sealed isocyanate, wherein the molar ratio of the 3, 5-dimethylpyrazole to the carbamate prepolymer is 3: 1;

(2) adding 200-250 times of water by mass into the blocked isocyanate, stirring at 1500-2500 rpm for 30-40 min to prepare blocked isocyanate emulsion, and mixing the blocked isocyanate emulsion with amino silicone oil according to a mass ratio of 1: 1, uniformly mixing to obtain the organic silicon modified waterborne polyurethane smoothing agent.

9. The three-proofing finishing process of pure cotton fabric according to claim 8, characterized in that: the amino silicone oil is TSF-4708 amino silicone oil.